Yep, I share your concern. If you don't have a setup that permits mounting the indicator such that the tip trails off the slots at a right angle, set the indicator so it has just barely picked up the table surface. As the head approaches a true condition, it need make contact by only a thou. Then, when you rotate past the slots, do it slowly. Use the largest ball tip you have for the DTI, assuming you have choices. I think you'll find it will work perfectly well, assuming you have a decent DTI. I have always used a B&S BesTest, and almost always mount the indicator in the less than desirable orientation. Works fine!abarton wrote:I understand. But when I sweep the DTI over the mill table surface in a 8" diameter arc, I cringe every time the probe tip drops into a T-slot. I don't have any idea how much abuse my little DTI can take, bouncing in and out of the slots.
Not in my opinion. I don't recommend the use of a stone, nor do I recommend the use of a new file. Both of them will remove metal where they shouldn't. By drawing the file with your palms as I suggested, and using one that has seen service (or one prepared as advised by JTiers), it won't be sharp enough to cut large surfaces, skating on them instead. When the slightest hump is encountered, the file will remove the top without removing any of the base metal, which should by your objective. A stone will remove metal anywhere it makes contact, albeit a tiny amount. Given a few years of that practice, you could materially effect the table surface.I recently went over the table surface with a 6" stone. I did find a few small dings and got them smoothed out to where I couldn't feel them through the stone any more. Is that as good as draw filing?
I have used the draw file method I suggested on the BP mill I currently own, which was purchased new in '77. The flaking on the table is equally bold and visible over the entire table surface. That likely would not have been the case had I used a stone.
Harold